Ipomoea bombycina (Choisy) Benth. & Hook

Wood, John R. I., Munoz-Rodriguez, Pablo, Williams, Bethany R. M. & Scotland, Robert W., 2020, A foundation monograph of Ipomoea (Convolvulaceae) in the New World, PhytoKeys 143, pp. 1-823 : 1

81. Ipomoea bombycina (Choisy) Benth. & Hook f. ex Hemsl., Biol. Cent.-Amer., Bot. 2: 384. 1882. (Hemsley 1882: 384)

Bombycospermum mexicanum C. Presl , Reliq. Haenk. 2: 137, t. 71. 1835. (Presl 1831-35: 137), non Ipomoea mexicana A. Gray (1878) . Type. MEXICO (west). Haenke s.n. (PR?, n.v.).

Batatas bombycina Choisy in A.P. de Candolle , Prodr. 9: 340. 1845. (Choisy 1845: 340). Type. Based on Bombycospermum mexicanum C. Presl

Type.

Based on Bombycospermum mexicanum C. Presl

Description.

Woody liana from a rough, furrowed hypocotyl, stem with yellowish bark, pubescent and scabrous-pustulate. Leaves petiolate, 2.5-7.5 cm, ovate-rhomboid, acute, margin somewhat undulate, base subtruncate and cuneate onto the petiole (sometimes asymmetric), adaxially glabrous, abaxially grey-tomentose, puncticulate, veins prominent; petioles 2-5 cm, pubescent, sometimes pustulate. Inflorescence of short leafy axillary racemes, sometimes reduced to tight clusters; rhachis 2-8 cm long, densely pubescent; bracteoles c. 5 mm long, linear, fugacious; pedicels 3-4(-8) mm; sepals 5-8 mm, grey-tomentose, subequal, outer ovate, acute, inner elliptic, obtuse; corolla 2.5-3.5 cm long, basal cylindrical tube 7-10 mm, then expanded, urceolate, tube cream with purplish veins, adpressed pilose, limb with short triangular lobes, c. 3 × 3 mm, yellowish-green. Capsules 15 × 8-10 mm, ellipsoid, glabrous; seeds 7 × 4 mm, blackish, densely woolly with hairs 2 cm or more long.

Distribution.

An uncommon endemic of southern Mexico.

MEXICO. Chiapas: Mun. Ocozocoautla de Espinoza, A. Shilom Tom 3761 (F). Guerrero: Acapulco, E. Palmer 370 (F, K, MO); ibid., F. Miranda 3342 (MEXU); Tecpan, E. Langlassé 939 (K). Jalisco: Tomatlán, Puerto Vallarta-Barra de Navidad, E.J. Lott 678 (FTG, MEXU, MO); La Huerta, M.G. Ayala 442 (MEXU); Coyuca-El Zapote, G.L. Webster & G.J. Breckon 16227 (MEXU). Oaxaca: Tapanatepec, D. Thomatis s.n. (K). Zacatecas: El Calabazal, E. Langlassé 479bis (K, P).

Notes. The corolla is consistently 3-3.5 cm long, not 2.5 cm, as stated by McDonald (1992) so corolla size is unreliable in separating this species from Ipomoea gesneriodes .

A night-flowering, possibly bat-pollinated species.

The specimen at MO (H.C. Cutler 8414) from Ceará, Brazil, identified as Ipomoea bombycina by McPherson is leafless and flowerless and is almost certainly not this species. It might, for example, be I. eremnobrocha , which has similar seeds and is known from several states in NE Brazil.